Ontario County District Attorney R. Michael Tantillo calls the involvement of a private investigator in the murder investigation against Rose Chase — the Stanley woman charged with causing the death of her husband, Adam Chase, last June — “unusual.”

But, he added, “in almost every case, some evidence is developed from unlikely sources.”

Rose, 31, was charged Dec. 14 with second-degree murder for allegedly “intentionally causing the death” of her husband of 11 years, Mr. Chase, 31, last June, said Ontario County Sheriff Philip Povero.

Shortly after Mr. Chase’s mother, Silvia Chase, reported him missing June 15, Rodney Miller said he began investigating his disappearance.

“I said, ‘I have to go and help find him,’” said Miller, of Gorham, who said he is a longtime friend of the Chase family. He declined to comment further on the investigation in order to not interfere with the case.

Mr. Chase’s disappearance was investigated as a missing-person case by the sheriff’s office until last month, when the sheriff’s office said information provided by Miller led investigators to re-interview Rose. They subsequently conducted searches of the Chases’ Mott Road home and a property owned by Rose’s mother at 4675 Haggerty Road in Potter, Yates County.

Povero said the investigation indicated Rose allegedly pushed Mr. Chase down two flights of stairs at their residence and transported his dismembered body to the property in Potter.

The case is expected to go before a grand jury this month, Tantillo said, adding that the involvement of a private investigator “doesn’t change anything in the grand jury.”

“Anyone with evidence can be subpoenaed to testify,” he said.

Tantillo said the grand jury will determine charges against Rose.

“The grand jury is authorized to consider the murder charge and any other charges they deem appropriate,” he said.

The charge of second-degree murder carries a maximum sentence of 25 years to life in prison, Tantillo said.